ABSTRACT NUMBER: ESOC2026A1030 PREDICTORS OF DELAYED NEUROLOGICAL IMPROVEMENT AFTER MECHANICAL THROMBECTOMY FOR ACUTE POSTERIOR CIRCULATION ISCHEMIC STROKE

Abstract Background and aims To investigate the incidence and predictors of delayed neurological improvement (DNI) in posterior circulation stroke (PCS) patients undergoing mechanical thrombectomy (MT). Methods This multicenter retrospective study (2020–2023) analyzed PCS patients treated with MT. DNI was defined as achieving a favorable functional outcome (mRS 0–3) at 3 months despite the absence of early neurological improvement (24h post-procedure). Independent predictors were identified via logistic regression to construct a nomogram, validated by the area under the curve (AUC). Results Of 256 patients, 188 (73.4%) exhibited no early improvement. Among them, 51 (27.1%) achieved DNI. Multivariate analysis identified male sex [OR 3.049 (1.064–8.738); P=0.038], lower baseline NIHSS [OR 0.891 (0.856–0.926); P<0.001], and higher PC-ASPECTS [OR 1.821 (1.255–2.641); P=0.002] as independent predictors. The nomogram demonstrated robust discriminative ability (AUC 0.87). Conclusions Approximately 27% of PCS patients lacking early clinical response to MT eventually achieve favorable functional outcomes. Male sex, lower initial stroke severity, and higher PC-ASPECTS independently predict DNI, providing crucial insights for prognostication and long-term management strategies. Conflict of interest The authors report no competing interests.